In a variety of consumer packaging applications, it is important to have paperboard containers which provide enhanced product protection during storage and transit and which provide evidence of tampering with the products within a container. Such paperboard containers are particularly important in applications involving containers which hold product sets. Without a strong, stable paperboard container, a product could break through an ill-handled container during transit, resulting in a ruptured container and an incomplete or damaged product set. In addition, without a tamper evidence closure, a portion of the product set could be removed from the paperboard container or tampered with prior to a sale to a consumer.
One exemplary container for holding product sets uses a hierarchy of multiple containers. Components of a product set are placed in small individual containers, and the small individual containers are subsequently placed in a single large container. The containers are sized so that the small containers snugly fit within the large container. The containers are typically designed using conventional seal end closures or tuck closures. Conventional tuck closures include "cereal-type" closures commonly used on dry cereal cartons, single tuck flap closures, closures using both a tuck flap and tongue lock, and edge lock closures which use a lock tab and associated lock slit.
In order to provide tamper evident closure, conventional containers use a combination of the "cereal-type" tuck closure and a tear strip. These containers are designed with two major flaps, an outer closure flap and an inner closure flap, hingedly connected to opposing side walls of the container. The outer closure flap includes a tear strip extending across the flap and a cereal-type lock slot positioned near the tear strip on the flap. The inner closure flap includes a lock tab along its outer edge. The container is originally sealed by gluing a portion of the outer closure flap over the inner closure flap. The container is opened by removing the tear strip from the outer closure flap, and the container is reclosed by placing the inner closure flap over the outer closure flap and interlocking the lock tab with the lock slot.
Conventional containers of the above-identified type suffer from disadvantages which severely restrict their use in certain consumer packaging applications, particularly where the packaged product constitutes a fragile product set. A major drawback of conventional containers which hold product sets is that a consumer is unable to view or access all of the products without opening both the single large container and the small individual containers contained within it. Opening every container to view or access all the products of a set is time-consuming and inconvenient. Another drawback of using a hierarchy of containers to package product sets is that an abundant amount of paperboard is required to produce all of the containers for holding the product sets. Yet another drawback for using a hierarchy of containers is the slow line speed for filling the containers with products, for the small individual containers are separately filled with products and are then inserted into the single large container. Furthermore, the present inventor has discovered that the aforementioned type of tamper evident closure does not provide a sufficient measure of security for fragile or heavy products. The inventor has found that once the container is opened by removing the tear strip and reclosed using the "cereal-type" closure, the "cereal-type" closure may accidently reopen due to pressure against the interlocking flaps. The lock tab and lock slot of the "cereal-type" closure cannot withstand much abuse without disengaging from one another.
Consequently, a need exists for improvements in the design of paperboard containers which will result in improved consumer viewability and accessibility of a product set within the container, provide tamper evident and strong positive closure, and provide enhanced product protection.